Or getting power users to buy the non-base models. I have a 2012 Mac Mini base model, and upgraded it to 16 GB RAM and a 256GB SSD for little cost. It should go without saying that I'll keep it for a while and probably double the SSD in some point in the future.
Even if those are quite rare, support incidents can be expensive, so it could be a dollar or two average per mini being saved.
Sure, I've had RAM break, but that was factory installed RAM that was several years old. This is definitely anecdata but it would be interesting to know how much damage static really does these days. If you're going out of your way to pet your cat prior to installing your RAM chips on a glass floor or something like that then you're probably asking for it. But regular precautions (place RAM container on the case before opening package, hold the case while inserting the RAM) seem to be more than enough. On chip ESD protection has come a long way since the 80's.
http://www.amazon.com/On-Chip-Protection-Integrated-Circuits...
B) Apple wants to capture the cost of upgrading their hardware in the future.
I think "capture" is the key word. They're not trying to create wealth for their users with this action; they're trying to capture it for their company and its shareholders.
They would like people to go buy a higher end model. The profit on RAM is probably pretty good given performance boost vs the cost of RAM. It is an opportunit they would be silly to waste.
There is always an excuse. In reality, they have changed their model to 'upgrades only at purchase'. Unfortunately, their machines are so good that we all accept this...